Wayne Gretzky entered the NHL in 1979, and by the time he retired 20 years later he had rewritten the NHL record book so thoroughly that it was unrecognizable. Gretzky set 61 league records, and 12 years later only one of them -- most career overtime assists -- has been broken. Many of the rest are so far ahead of their runners-up that we wonder if they would be broken even if the NHL lasts for another 100 years.